Carb Sync on '78 GS550

[Anonymous]

I am going to attempt my first carb sync tonight on my '78 gs550. I just purchased a Morgan II carbtune manometer and I have read LOTS of usefull info on this site about doing carb syncs and I will attempt to follow the advice as best as I can

My question is:
I believe my '78 has VM carbs, right? Does this mean that carb #3 is the master carb? or do I have to adjust all 4 carbs?

[Rock]

You have to check and adjust all four as needed.

[ptm]

The VMs don't have a 'master' carb. The most important thing is that they are all the same, but I think Earl has talked about going an extra step and setting them to 12 in (24cm) hg @ 1800 rpm, but I'm not sure if that is for all models or just the 750. Do some searches and you can probably find the original thread.

Be sure the valve clearance is good and the timing is set properly before you sync.

[KEITH KRAUSE]

Some VM carbs do have a master carb, which is #3.
It's easy to tell. If a master carb, there's no throttle valve adjuster screw above the throttle valve.

[Anonymous]

Carb sync went well and it runs alot smoother now.
FYI: it did not have a master carb; I had to adjust all 4 carbs.

At first I couldn't figure out why carb 3 had no vacum reading, then I realized that when the gas tank is off, you have to plug up the vacum line. Only took a few mins to sync once I did that. Also I did double and triple checks after I tightened the lock nuts. And I was glad I did as some of the adjustments were off after I locked them.

Also, I read somewhere in this forum to use fans to help cool the engine while syncing. I used 2 good sized fans on full power to help keep the engine cool.

Thanks again for the advice...